Diafiltration is used in biotechnological applications for buffer exchange and product recovery, depending on mode of operation. In diafiltration, buffer is introduced into a recycle or retentate tank while filtrate is removed from the system. Diafiltration can be used as a method of washing a retentate that is the product or to wash product through the filtration system for collection. It is a goal of microfiltration harvest processes that use diafiltration to maximize recovery of product from the process stream.